As a prefilled syringe in which an injection solution is filled, many proposals have been made. The present applicant proposed such a prefilled syringe as disclosed in the specification of Japanese Patent Application Laid-Open Publication No. 2013-203675 (patent document 1).
The dexmedetomidine used in the invention of the patent document 1 is a compound, having a sedative action, which is a central α2-adrenergic receptor agonist being strong and having a high selectivity.
As an injection formulation, a rocuronium bromide injection formulation is known. The rocuronium bromide is a compound which acts as an antagonist against a nicotinic acetylcholine receptor present in the postsynaptic membrane of neuromuscular junctions and thus has a nondepolarizing muscle relaxation action of antagonizing the transmission of acetylcholine-caused excitement from nerves to muscles.
A rocuronium bromide injection formulation is used to relax muscles at an anesthetic administering time and a tracheal intubation time. Thus the rocuronium bromide injection solution is a formulation having a high possibility of being used at an emergent administration time. The rocuronium bromide injection formulation is a vial formulation to be administered intravenously or continuously. Thus workloads including the transfer of a liquid medicine to a syringe barrel have become a problem in medical fronts. Thus there is a strong demand for the improvement of the formulation from the medical front.
A prefilled syringe in which a liquid medicine is filled in advance has been conventionally used to prevent medicines from being mixed up, prevent nosocomial infection, improve disposability, and increase the efficiency of hospital service. As the material for the prefilled syringe, glass and various plastics have been used. Because the prefilled syringe made of synthetic resin is lighter and more resistant to breakage than the prefilled syringe made of glass, the use of the prefilled syringe made of the synthetic resin allows dispensing works to be performed more safely than the prefilled syringe made of glass in the medical front.
From the above-described standpoint, it is preferable to use the rocuronium bromide injection solution for the formulation to be filled in the prefilled syringe made of synthetic resin. But there is a case in which a medicine has interaction with an outer cylinder of the syringe or a gasket made of rubber. Thus it is conventionally necessary to investigate the use of the rocuronium bromide injection solution for the prefilled syringe. Because the rocuronium bromide contained in the rocuronium bromide injection solution as its main component is stable in an aqueous solution whose pH is about four, the rocuronium bromide is formulated under an acidic condition.